Question

Which algorithm can be used to sign a message?

(a) Public key algorithm

(b) Private key algorithm

(c) Public & Private key algorithm

(d) None of the mentioned

This question was addressed to me in an internship interview.

I'd like to ask this question from Public Key Cryptosystems in chapter Encryption and Decryption of Digital Communications

Answer 1

The correct choice is (a) Public key algorithm

The explanation is: Public key algorithms are used to sign a message and private key algorithms are used to encrypt the messages.